Continuous operation of a device such as a computer keyboard or mouse may lead to fatigue or discomfort in the region of the operator's hand or wrist. Additionally, continuous operation over a substantial period of time may lead to repetitive motion stress injury such as carpal tunnel syndrome.
To relieve fatigue and inhibit the onset of repetitive motion stress injury, various supports for the operator's hand or wrist have been proposed. For example, some supports aim to maintain the operator's hand or wrist in a predetermined, ergonomically desirable orientation during operation of a keyboard or mouse. In such supports, the operator's hand or wrist is supported on a rigid surface.
U.S. Pat. Nos. 5,674,423 and 5,686,005 disclose a heated pad especially adapted for use in conjunction with a computer keyboard or mouse. The top surface of the pad includes a support surface for a user's wrist, this surface being planar or having a curved depression. An electrical heating unit is embedded in a layer beneath the support surface, such that heat is delivered to the operator's hand and wrist during operation of the keyboard or mouse, and thereby treats stress to the hand and wrist while operating the keyboard or mouse. The support described in these patents supplies heat to the operator's wrist or hand, but the support is rigid. Additionally, assembly or manufacture of such a device is relatively complicated.